This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited stronger antimicrobial activities.Compound 5 was the most active while Staphylococcus aureus and Candida albicans were sensitive to all the tested compounds.The existence of a relationship between the xanthone structures and inhibition of microorganism activity.The antimicrobial activity of this plant was reported here firstly.The results provided evidence that the studied plant extract,fractions as well as some of the isolated compounds might be potential sources of new antimicrobial drug.